This invention relates generally to corrosion-resistant caps used in connection with fastener and in particular, to corrosion-resistant caps used with moisture-proof, elastomeric washers.
A corrosion-resistant cap for a fastener is disclosed in U.S. Pat. No. 4,460,300 (Bettini et al.). The cap has a single skirt which is bent and crimped beneath the head of the fastener. A sealing washer is placed between the lower surface of the cap and the object in which the fastener is placed to provide a moisture and weather resistant seal after the fastener is tightened.
A similar cap is disclosed in U.S. Pat. No. 3,803,972 (Deutsher) which specifies a cap having a skirt which is crimped beneath the flange on the head of the fastener. It also uses a washer with a resilient material to provide a tight seal. The caps of both Bettini and Deutsher are used with fasteners which have downwardly sloping flanges. The fasteners are used to connect two panels together, with the upper panel having a hole therein to form a cavity into which the washer is placed and in which elastomeric material of the washer will flow.
However, none of the presently available caps disclose a cap with an inner and outer skirt. The inner skirt is swaged or bent beneath the flange of the fastener so that the inner surface of the inner skirt makes contact with and covers the lower surface of the flange. Thus, the entire head and flange of the fastener are enclosed by the cap material without the necessity for bending the outer skirt, which reduces the diameter of the skirt, resulting in a more positive and tighter seal than heretofore available.